Circuit board bypass assemblies and components therefor

ABSTRACT

A connector for use in a free-standing connector port for mating with an external pluggable module is disclosed. The connector has terminals that extend lengthwise of the connector so that cables may be terminated to the terminals and the terminals and cable generally are horizontally aligned together. The connector defines a card-receiving slot and is position in a cage that defines the connector port. The cables exit from the rear of the connector and from the connector port. The connector includes a heat sink that is configured to cool a module inserted into the connector port.

RELATED APPLICATIONS

This application claims priority to U.S. Ser. No. 16/823,333, filed Mar.19, 2020, now U.S. Pat. No. TBD, which in turn claims priority to U.S.Ser. No. 16/110,727, filed Aug. 23, 2019, now U.S. Pat. No. 10,637,200,which in turn claims priority to U.S. Ser. No. 15/541,775, filed Jul. 6,2017, now U.S. Pat. No. 10,135,211, which in turn claims priority toInternational Application No. PCT/US2016/012848, filed Jan. 11, 2016,which in turn claims priority to prior U.S. provisional patentapplication No. 62/102,045, filed Jan. 11, 2015 entitled “The MolexChannel”; prior U.S. provisional patent application No. 62/102,046,filed Jan. 11, 2015 entitled “The Molex Channel”; prior U.S. provisionalpatent application No. 62/102,047, filed Jan. 11, 2015 entitled “TheMolex Channel”; prior U.S. provisional patent application No. 62/102,048filed Jan. 11, 2015 entitled “High Speed Data Transmission ChannelBetween Chip And External Interfaces Bypassing Circuit Boards”; priorU.S. provisional patent application No. 62/156,602, filed May 4, 2015,entitled “Free-Standing Module Port And Bypass Assemblies Using Same”,prior U.S. provisional patent application No. 62/156,708, filed May 4,2015, entitled “Improved Cable-Direct Connector”; prior U.S. provisionalpatent application No. 62/156,587, filed May 4, 2015 entitled “LEDIndicator Light Assembly for Module Ports and Ports Incorporating Same”;prior U.S. provisional patent application No. “62/167,036, filed May 27,2015 entitled “Wire to Board Connector with Wiping Feature and BypassAssemblies Incorporating Same”; and, prior U.S. provisional patentapplication No. 62/182,161, filed Jun. 19, 2015 entitled “Wire to BoardConnector with Compliant Contacts and Bypass Assemblies IncorporatingSame”, all of which are incorporated herein by reference in theirentirety.

TECHNICAL FIELD

This disclosure relates to field of high frequency signaling

DESCRIPTION OF RELATED ART

The Present Disclosure relates generally to high speed data signaltransmission line systems suitable for use in transmitting high speedsignals at low losses from chips, or processors and the like tobackplanes, mother boards and other circuit boards, and moreparticularly to an assembly that interconnects the chip package of adevice to entry and exit connectors without utilizing traces on acircuit board, shielded connector ports for the entry and/or exitconnectors, heat sinks for the connector ports, cable-direct connectorsutilized in the shielded connector ports and indicator light assembliesutilized with the connectors and connector ports.

Electronic devices such as routers, servers, switches and the like needto operate at high data transmission speeds in order to serve the risingneed for bandwidth and delivery of streaming audio and video in many enduser devices. These devices use signal transmission lines that extendbetween a primary chip member mounted on a printed circuit board (motherboard) of the device, such as an ASIC, FPGA, etc. and connectors mountedto the circuit board. These transmission lines are formed as conductivetraces on or in the mother board and extend between the chip member(s)to external connectors or circuitry of the device.

Typical circuit boards are usually formed from an inexpensive materialknown as FR4, which is inexpensive. Although inexpensive, FR4 is knownto be lossy in high speed signal transmission lines which transfer dataat rates of about 6 Gbps and greater (e.g., above 3 GHz signalingfrequencies). These losses increase as the frequency increases andtherefore make FR4 material undesirable for the high speed data transferapplications at signaling frequencies of about 10 GHz and greater. Inorder to use FR4 as a circuit board material for high frequency signaltransmission lines, a designer may have to utilize amplifiers andequalizers, which increase the final cost of the device.

The overall length of the signal transmission lines in FR4 circuitboards can exceed threshold lengths, about 10 inches, and may includebends and turns that can create signal reflection and noise problems aswell as additional losses. Losses can sometimes be corrected by the useof amplifiers, repeaters and equalizers but these elements also increasethe cost of manufacturing the final circuit board. This complicates thelayout of the circuit board as additional board space is needed toaccommodate these amplifiers and repeaters. In addition, the routing ofsignal transmission lines in the FR-4 material may require multipleturns. These turns and the transitions which occur at termination pointsalong the signal transmission lines may negatively affect the integrityof the signals transmitted thereby. It then becomes difficult to routetransmission line traces in a manner to achieve a consistent impedanceand a low signal loss therethrough. Custom materials, such as Megtron,are available for circuit board construction which that reduce suchlosses, but the prices of these materials severely increase the cost ofthe circuit board and, consequently, the electronic devices in whichthey are used.

Integrated circuits (often referred to as chips) are the heart of theseelectronic devices. These chips typically include a processor such as anapplication specific integrated circuit (ASIC) chip and this ASIC chiphas a die that can be connected to a substrate (its package) by way ofconductive solder bumps. The package may include micro-vias or platedthrough holes which extend through the substrate to solder balls. Thesesolder balls can comprise a ball grid array by which the package isattached to the motherboard. The motherboard includes numerous traceswhich designated define transmission lines that include differentialsignal pairs, ground paths associated with the differential signalpairs, and a variety of low speed transmission lines for power, clocksignals and other functions. These traces are routed from the ASIC tothe I/O connectors of the device into which external connectors areconnected, as well as others that are routed from the ASIC to backplaneconnectors that permit the device to be connected to an overall systemsuch as a network server or the like, or still others that are routedfrom the ASIC to components and circuitry on the motherboard or anothercircuit board of the device.

FR4 circuit board materials can handle data transmission speeds of 10Gbits/sec, but this handling comes with disadvantages. Increased poweris required to transmit signals over longer trace lengths, so designersfind it difficult to provide “green” designs, as low power chips cannoteffectively drive signals for such lengths. The higher power needed todrive the high speed signals over these lengths consumes moreelectricity and generates more heat that must be dissipated.Accordingly, these disadvantages further complicate the use of FR4 as amotherboard material used in electronic devices. Using more expensive,and exotic motherboard materials, such as Megtron, to handle the highspeed signals at more acceptable losses increases the overall cost ofelectronic devices. Notwithstanding the low losses experienced withthese expensive materials, they still require increased power totransmit their signals and incurred, and the turns and crossoversrequired in the design of lengthy board traces create areas of signalreflection and potential increased noise. Consequentially, certainindividuals would appreciate further improvements.

SUMMARY

In accordance with the Present Disclosure, a bypass assembly is used toprovide a high speed data transmission line extending between a devicechip or chip set and backplanes or circuit boards. The bypass cableassemblies include cables which contain signal transmission lines thatavoid, or bypass, the disadvantages of circuit board construction, nomatter the material of construction, and which provide independentsignal paths which have a consistent geometry and structure whichresists signal loss and maintains impedances at acceptable levels.

In such applications, an integrated circuit having the form of a chip,such as an ASIC or FPGA, is provided as part of an overall chip package.The chip is mounted to a package substrate by way of conventional solderbumps or the like and may be enclosed within and integrated to thesubstrate by way of an encapsulating material that overlies the chip anda portion of the substrate. The package substrate has traces, or leads,that extend from the solder bumps on the chip bottom to a terminationarea on the substrate. Cables which are terminated to the substrate attheir near ends, are used to connect the chip circuits to externalinterfaces of the device in which the chip is used, such as I/Oconnectors, backplane connectors and circuit board circuitry.

The chip package may include a plurality of contacts in the form ofsolder balls disposed on the underside of a chip package for providingconnections to and from logic, clock, power and low-speed and high speedsignal circuits to traces on the motherboard of a device in which thechip package is used. The contacts associated with the high speed signalcircuits of the chip are removed from the bottom of the chip packageinasmuch as the high speed traces are no longer routed to the bottom ofthe chip package. Some traces of the chip package may continue to berouted to the bottom of the package such as clock signals, logicsignals, low speed signals and power. The termination locations forthese traces are easily routed on the top of the chip package substratewhere they can be easily connected to cables in a manner that maintainsthe geometry of the cable signal transmission lines. The high speedsignal traces of the chip package are no longer routed through platedthrough holes, micro-vias, solder balls or a multilayer circuit board.Such a bypass assembly removes the signal transmission lines from themotherboard, not only alleviating the loss and noise problems referredto above, but also freeing up considerable space (i.e., real estate) onthe motherboard, while permitting low cost circuit board materials, suchas FR4, to be used for its construction.

Cables utilized for such assemblies are designed for differential signaltransmission and preferably are twin-ax style cables that utilize pairsof signal conductors encased within dielectric coverings to form twowires, or a signal wire pair. The wire pairs may include associateddrain wires and the three constituent wires of each such signal pair mayfurther be enclosed within an outer shield in the form of a conductivewrap, braided shield or the like. In some instances, the two conductorsmay be encased in a single dielectric covering. The spacing andorientation of the wires that make up each such wire pair can be easilycontrolled in a manner such that the cable provides a transmission lineseparate and apart from the circuit board, and which may extend betweena chip, chip set, component and a connector location on the circuitboard or between two locations on the circuit board. The orderedgeometry of the cables as signal transmission lines components is veryeasy to maintain and with acceptable losses and noise as compared to thedifficulties encountered with circuit board signal transmission lines,no matter what the material of construction.

First ends of the wire pairs are typically terminated to correspondingchip packages and second ends these wire pairs are terminated directlyto terminals of entry or exit port connectors, such as I/O and backplaneconnectors. In at least the terminations to one set of the connectors,the second ends of the wire pairs are terminated in a manner and spacingthat emulates the ordered geometry of the cable so that crosstalk andother deleterious factors are kept to a minimum at the connectorlocation and all of the connector terminals have the same length. Thefree ends of the signal terminal pairs are arranged in desired spacingsand include associated grounds so that the ground associated with eachwire pair may be terminated to a corresponding ground of the connectorto define an associated ground that extends the entire length of thecable and its connector. This arrangement will provide shielding, andreduction of cross talk, by defining a ground plane to which the signalterminals can couple in common mode, while pairs of signal terminals cancouple together in differential mode. The termination of the cable wiresto the connectors is done in a manner such that to the extent possible,a specific desired geometry of the signal and ground conductors in thecable is maintained through the termination of the cable to theconnector.

A single chip package may be provided that includes an integratedcircuit mounted to a substrate. The substrate has termination areas towhich first ends of a plurality of twin-ax cables are terminated. Thelengths of the cables may vary and will be long enough for some of thecables to be easily and reliably terminated to first external interfacesin the form of a single or multiple I/O style connectors of the presentdisclosure which are part of an external connector port of either, orboth of the entry and exit connectors. These connectors may bepreferably mounted to a panel of the host device in a fashion thatpermits external connectors, such as plug connectors or pluggablemodules to be mated therewith. The assemblies of the present disclosuremay have their cables extend between entry connectors of the device andthe chip package formed as an integrated assembly, or they may furtherinclude additional cables that extend between the chip package and exitconnectors of the device. The first ends of the bypass cables may beconfigured so that they may be inserted into connectors on the chippackages so as to have “plug and play” capability. In this manner, theexternal connector ports can be inserted into the host device as singleor ganged elements, each containing one or more signal transmissionchannels. The chip package may be supported within the housing of thedevice either solely or by way of standoffs or other similar attachmentsto a low cost, low speed motherboard.

Removing the signal transmission lines from the chip to the externalconnector ports off of the motherboard in this manner frees up space onthe motherboard which can accommodate additional functional componentsto provide added value and function to the device, while maintaining acost that is lower than a comparable device that utilizes themotherboard for signal transmission lines. Furthermore, incorporatingthe signal transmission lines in the cables of the bypass assemblyreduces the amount of power needed to transmit high speed signals fromthe chip packages to the external connectors, thereby increasing the“green” value of the bypass assembly and reducing the operating cost ofdevices that use such bypass assemblies.

The cables extending between connectors of the present disclosure andthe chip packages are of the “twin-ax” style, with two wires each with asignal conductor running lengthwise of the wire, enclosed in adielectric covering. The pairs of wires are preferably terminated toreceptacle connectors at the proximal ends of the cables and at theirdistal ends directly to the chip packages. The receptacle connectors arepreferably contained within a port structure, such as a cage, adapterframe or the like and cooperate with the port structure to define ashielded module housing configured to receive an external connector,such as a pluggable module. The second ends of the cable wires areterminated directly to the terminals and grounds of the receptacleconnectors, and the cables are preferable held in wafer-like supports todefine terminal rows on opposing sides of card-receiving slots of thereceptacle connectors. The cables exit the port structure through therear wall thereof. By using this direct connection between the cablewires and receptacle connectors, a designer can avoid using connectorswith right angle board connectors, which are known to create noise andimpedance problems. The signal and ground terminals of this cable-directconnector all extend horizontally and are of the same length. Thissubstantially removes the signal integrity and impedance discontinuityproblems associated with right-angle connectors, which include terminalsof different lengths.

Because the receptacle connectors are contained entirely within the portstructure and not directly connected to a circuit board, the bottom wallof the housing can be continuous in its extent completely seal off thebottom of the housing which greatly improves the EMI performance of theconnector port. The use of press-fit pins to mount the connector portsare also eliminated. Pairs of connector elements in the form of wafersare provided which fit into an opening in the rear of the receptacleconnector. A primary ground plane is provided between the connectorelements to block signal interference, such as crosstalk, between thesignal terminals of the two connector elements. Accordingly, theconnector ports of the present disclosure may be mounted individually toa face panel or a wall of the host device, or even interconnected withother ports to form an integrated assembly of ports that are suitablefor vertical or horizontal stacking. Furthermore, if desired, theconnector port can be positioned within the host device as an internaltransition connector that can be supported on a circuit board, onstandoffs or other supports or stand alone. This structure definesconnector ports with high speed connectors that form signal transmissionlines useful for high speed data applications at 10 Gbps or above andwith low loss characteristics which bypasses circuit traces on the hostdevice circuit board.

The operational speeds of the devices in which the above-describedassemblies are use operate at high data transmission speeds andaccordingly, generate heat during data transmission. The shieldedconnector port of the present disclosure may further include a heat sinkassembly that extends into an interior portion of the housing and whichis configured to make contact with the mating module inserted into thehousing. The housing includes walls that cooperatively define theinterior which houses a receptacle connector. Inasmuch as these housingsmay often be mounted along a face panel of the host device, a heat sinkassembly is provided that includes a transfer portion which makescontact with the mating module inserted into the housing, and adissipating portion connected thereto, which is uniquely spaced apartfrom the transfer portion in a horizontal direction. In this manner, theheat-dissipating portion extends rearwardly of the shielded housing andwill include downward facing fins. This structure takes advantage of theopen space behind the housing and may provide a reduction in overallheight of the host device.

In order to provide indicator lights for use in association with theabove described connectors ports that utilize the aforementioned heatsinks, an indicator light arrangement may be utilized that has aplurality of LEDs, either free standing or aggregated together in theform of a light bar which is mounted to the connector port proximate tothe face panel or bezel of the host device. The LEDs are connected byflexible wires to circuits in the circuit board, and the wires permitflexibility in connecting the LEDs to circuitry which does not requireancillary structural supports as is the case with light pipes. The lightbar may include one or more retaining clips, or arms, which are used tohold the heat transfer member of the heat sink, saving manufacturingcost by integrating the two members together.

This type of connection permits unobstructed airflow through anassociated heat sink supported by the housing, furthers frees up spacein the circuit board behind the housing, and saves cost in routing themother board as the LEDs are no longer positioned behind, underneath oralongside the housing. This structure does away with the need forsupport members that attach to the cage to support conventional lightpipes and thereby opens up the areas above and alongside the connectorports so that they can be stacked vertically or horizontally moreeasily. Still further such a structure permits the connector port to beused as a free-standing housing not supported by a circuit board as theinternal receptacle connector has directly connected to its terminals,thereby eliminating impedance discontinuities normally associated withconnector terminations to circuit board. The placement of the LEDswithout using light pipes or any sort of elongated light transmissionmember also reduces the likelihood of crosstalk from occurring.

All of the components can be combined together in a manner so that thecables, cable-direct connector, connector housing, heat transfer memberand indicator light bar all cooperatively form an integrated assemblythat may be connected directly to a chip package to define a high speedtransmission channel assembly that does not utilize lossy traces on acircuit board. Such a transmission channel assembly may also include apreselected chip in the chip package so that the entire assembly can beplugged into a host device after the bulk of the device has beenfabricated. The use of integrated assemblies such as those describedherein reduces the number of assembly steps and the cost ofmanufacturing of the host devices.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and not limitedin the accompanying figures in which like reference numerals indicatesimilar elements and in which:

FIG. 1 is a perspective view of an electronic device, such as a switch,router or the like with its top cover removed, and illustrating thegeneral layout of the device components and a bypass cable assembly inplace therein;

FIG. 2 is the same view as FIG. 1, with the bypass assembly removed fromwithin the device for clarity;

FIG. 2A is a perspective view of only the bypass assembly of FIG. 2;

FIG. 2B is the same as FIG. 2A, but with the chip package substrateand/or encapsulant removed for clarity;

FIG. 2C is an enlarged detail view of the termination area surroundingone chip used in the bypass assembly of FIG. 1;

FIG. 2D is a perspective view of the end of a twin-ax cable used in thebypass assemblies of the present disclosure;

FIG. 3A is a schematic cross-sectional view of a known structuretraditionally used to connect a chip package to a motherboard in anelectronic device such as a router, switch or the like, by way of tracesrouted through or on the motherboard;

FIG. 3B is a schematic cross-sectional view, similar to FIG. 1A, butillustrating the structure of bypass assemblies such as that illustratedin FIG. 1, which are used to connect a chip package to connector portsor other connectors of the device of FIG. 1, utilizing cables andconsequently eliminating the use of conductive traces as signaltransmission lines on the motherboard as illustrated in the device ofFIG. 1;

FIG. 4 is a perspective view of a cable-direct connector assemblyconstructed in accordance with the principles of the present disclosure;

FIG. 4A is a sectional view of the connector assembly of FIG. 4, takenalong lines A-A thereof;

FIG. 5 is an exploded view of a connector housing and the cable-directconnector assembly of FIG. 4;

FIG. 5A is the same as FIG. 5, but with the receptacle connector inplace within the housing and the bottom fixed to the sidewalls of thehousing;

FIG. 6 is a perspective view taken from the bottom, of the connectorhousing of FIG. 5, with the bottom wall removed and the connectorassembly removed out from inside of the housing;

FIG. 6A is the same view as FIG. 6, but with the connector assembly inplace within the connector housing;

FIG. 6B is the same view as FIG. 6A, but with the bottom wall in placeto seal the cable direct connector assembly in the connector housing;

FIG. 7 is a partially exploded view of the connector assembly of FIG. 4;

FIG. 8 is a more fully exploded view of the connector assembly of FIG.7;

FIG. 8A is an exploded view of one terminal array of the connectorassembly, its associated ground plates and a set of corresponding cablesand wires used in the connector assembly of FIG. 4;

FIG. 8B is the same view as FIG. 8A, but illustrating the componentsthereof in an assembled state to form a basic connector element;

FIG. 8C is a perspective view of two basic connector elements assembledtogether to form a receptacle connector terminal array;

FIG. 8D is an enlarged detail view of two of the cables in a connectorelement, illustrating the elevated ground plate structure utilizedtherewith;

FIG. 9 is a front elevational view of the connector housing illustratinga portion of an edge card contacting the terminal contact portions ofthe connector assembly;

FIG. 10 is an enlarged detail view, of the bottom of the rear end of aconnector housing with the connector assembly in place;

FIG. 11 is a perspective view of a connector housing of the presentdisclosure which is utilized in the bypass assemblies thereof;

FIG. 11A is a sectional view of the connector port of FIG. 11, takenalong lines A-A thereof;

FIG. 11B is a side elevational view of FIG. 11A;

FIG. 12 is a perspective view of the connector port of FIG. 11, buttaken from the rear of the opposite side;

FIG. 13 is a bottom plan view of the connector port of FIG. 6A, with thebottom removed for clarity;

FIG. 13A is a sectional view of an empty connector housing without theinternal connector and heat transfer member in place;

FIG. 14 is a top plan view of the connector housing with the top wallremoved from the housing body and a portion of an edge card engaged withthe internal connector;

FIG. 14A is the same view as FIG. 14, but sectioned at a level beneaththe rear cover plate to illustrate the internal connector and the mannerin which it engages the body of the connector housing;

FIG. 14B is a vertical sectional view taken through the housing bodyproximate to the front of the internal connector, with a portion of theinternal connector housing removed for clarity to illustrate the hollowinterior space of the module housing and the internal ribs thereof whichcontact the connector elements and hold an EMI absorbing pad in placethereof;

FIG. 15 is a perspective view of a pair of connector housings with heattransfer members and indicator lights arranged in a vertical stack on acircuit board;

FIG. 15A is an exploded view of FIG. 15;

FIG. 16 is a perspective view of three module housings arrangedvertically in a horizontal row on face plates of a device;

FIG. 16A is an exploded view of a vertical module housing and face platemounting assembly:

FIG. 17 is a perspective view of a module housing with an improved heatsink assembly constructed in accordance with the principles of thepresent disclosure attached thereto;

FIG. 18 is a partially exploded view of the module housing-heat sinkassembly of FIG. 17, with the heat sink assembly components removed fromtheir engagement with the top of the module housing for clarity;

FIG. 18A is a side view of the exploded view of FIG. 18, with thecomponents depicted therein sectioned along lines C-C thereof;

FIG. 19 is a front elevational view of the module housing-heat sinkassembly of FIG. 17, taken along lines 3-3 thereof;

FIG. 19A is a side elevational of the module housing-heat sink assemblyof FIG. 17, taken along the right side thereof;

FIG. 19B is a top plan view of the module housing-heat sink assembly ofFIG. 17;

FIG. 19C is a longitudinal sectional view of the module housing-heatsink assembly of FIG. 17, taken along lines C-C thereof;

FIG. 19D is a transverse sectional view taken through the modulehousing-heat sink assembly in the transfer portion of the heat sinkassembly of FIG. 17, taken along lines D-D thereof;

FIG. 19E is the same view as FIG. 19D, but with the heat pipe removedfrom the heat sink assembly for clarity and with an alternateconfiguration of a pair of heat pipes shown in phantom;

FIG. 19F is a transverse sectional view, looking rearwardly, takenthrough the module housing-heat sink assembly in the dissipating portionof the heat sink assembly of FIG. 17, taken along lines F-F thereof;

FIG. 19G is a transverse sectional view, looking forwardly, takenthrough the module housing-heat sink assembly in the dissipating portionof the heat sink assembly of FIG. 17, taken along lines G-G thereof,illustrating the clearance between the heat-dissipating fins and theconnector wires;

FIG. 20 is a perspective view of a connector port of the presentdisclosure with an indicator light assembly supported thereon;

FIG. 20A is an exploded view of the assembly of FIG. 20;

FIG. 20B is a front elevational view of the assembly of FIG. 20;

FIG. 20C is a top plan view of the assembly of FIG. 20;

FIG. 20D is a side elevational view of the assembly of FIG. 20;

FIG. 21 is a perspective view of the indicator light assembly of FIG.20, oriented as if it were attached to a connector port;

FIG. 22 is a perspective view of a pair of connector ports withindicator light assemblies supported thereon, stacked together in avertical orientation;

FIG. 23 is a perspective view of three connector ports and associatedindicator light assemblies stacked together in a horizontal orientation;

FIG. 24 is a perspective view of an indicator light assembly in place ona connector port with a thermal transfer member having itsheat-dissipating fins located on the top of the housing portion of theport, illustrating the path of the indicator light wires; and,

FIG. 24A is an exploded view of the assembly of FIG. 24.

DETAILED DESCRIPTION

The detailed description that follows describes exemplary embodimentsand is not intended to be limited to the expressly disclosedcombination(s). Therefore, unless otherwise noted, features disclosedherein may be combined together to form additional combinations thatwere not otherwise shown for purposes of brevity.

Accordingly, there is provided herein, an improved connector for use ina connector port that is connected directly to cables or wires, ratherthan traces on circuit boards to define signal transmission lines fromthe connector and directly to chips and processors of the host device,which are useful for high speed data applications at 10 Gbps and aboveand with low loss characteristics. Accordingly, the Present Disclosureis therefore directed to connectors and connector assemblies that aresuitable for use in free standing external connector ports and which aredirectly connected to device components by cables, rather than usetraces on circuit boards. The connectors have terminals and cables ofequal length and the cables terminated to the connector bypass thecircuit board traces and define high speed transmission lines fortransmitting data signals, at 10 Gbps and greater, which have low losscharacteristics and which are directly connected to the chips andprocessors of the host device.

As such, references to a feature or aspect are intended to describe afeature or aspect of an example of the Present Disclosure, not to implythat every embodiment thereof must have the described feature or aspect.Furthermore, it should be noted that the description illustrates anumber of features. While certain features have been combined togetherto illustrate potential system designs, those features may also be usedin other combinations not expressly disclosed. Thus, the depictedcombinations are not intended to be limiting, unless otherwise noted.

In the embodiments illustrated in the Figures, representations ofdirections such as up, down, left, right, front and rear, used forexplaining the structure and movement of the various elements of thePresent Disclosure, are not absolute, but relative. Theserepresentations are appropriate when the elements are in the positionshown in the Figures. If the description of the position of the elementschanges, however, these representations are to be changed accordingly.

FIG. 1 is a perspective view of a host electronic device 50 such as aswitch, router, server or the like, and with the cover of the hostdevice removed. The device 50 is governed by one or more processors, orintegrated circuits, in the form of chips 52 that may be part of anoverall chip package 54. The device 50 has a pair of side walls 55 andfirst and second walls, 374, 57. External connector ports 80 areprovided in the first wall 374 (which can be a front wall) of the hostdevice so that opposing mating connectors in the form of pluggablemodules and the like may be inserted in order to connect to circuits ofthe device 50. Backplane connectors 30 may be provided in a second wall57 (which can be a back wall) for connecting the device 50 to a largerdevice, such as a server or the like, including backplanes utilized insuch devices. The device 50 includes a power supply 58 and coolingassembly 59 as well as a motherboard 62 with various electroniccomponents thereupon such as capacitors, switches, smaller chips, etc.

FIG. 3A is a cross-sectional view of a prior art conventional chippackage and motherboard assembly that is used in conventional devices.The chip 52 may be an ASIC or any another type of processor orintegrated circuit, such as a FPGA and may be one or more separateintegrated circuits positioned together. Accordingly, the term chip willbe used herein as a generic term for any suitable integrated circuit. Asshown in FIG. 3A, the chip 52 has contacts on its underside in the formof solder bumps 45 that connect it to associated contact pads of asupporting substrate 47. The substrate 47 typically includes platedthrough-holes, micro-vias or traces 48 that extend through the body ofthe substrate 47 to its underside. These elements 48 connect withcontacts 49 disposed on the underside 47 a of the substrate 47 and thesecontacts 49 typically may take the form of a BGA, PGA or LGA and thelike. The chip 52, solder bumps 45, substrate 47 and contacts 49 allcooperatively define a chip package 52-1. The chip package 52-1 ismated, by way of a socket (not shown) to a motherboard 52-2 made of FR4material and used in a device. The motherboard 62 has a plurality oflengthy conductive traces 52 a-c that extend from the chip packagecontacts 49 through the motherboard to other connectors, components orthe like of the device. For example, a pair of conductive traces 52 a,52 b are required to define differential signal transmission line and athird conductive trace 52 c provides an associated ground that followsthe path of the signal transmission line. Each such signal transmissionline is routed through or on the motherboard and such routing hascertain disadvantages.

FR4 circuit board material becomes increasing lossy and at frequenciesabove 10 Ghz this starts to become problematic. Additionally, turns,bends and crossovers of these signal transmission line traces 52 a-c areusually required to route the transmission line from the chip packagecontacts 49 to connectors or other components mounted on the motherboard52-2. These directional changes in the traces 52 a-c can create signalreflection and noise problems as well as additional losses. Losses cansometimes be corrected by the use of amplifiers, repeaters andequalizers but these elements also increase the cost of manufacturingthe final circuit board 52-2. This complicates the layout of the circuitboard 52-2 because additional board space will be needed to accommodatesuch amplifiers and repeaters and this additional board space may not beavailable in the intended size of the device. Custom materials forcircuit boards are available that reduce such losses, but the prices ofthese materials severely increase the cost of the circuit board and,consequently, the electronic devices in which they are used. Stillfurther, lengthy circuit traces require increased power to drive highspeed signals through them and, as such, they hamper efforts bydesigners to develop “green” (energy-saving) devices.

FIG. 3B is a cross sectional view of the chip package 54 of the device50 of FIG. 1. The chip 52 contains high speed, low speed, clock, logic,power and other circuits which are connected to the chip packagesubstrate 53. Traces 54-1 of the package 54 lead to associated contactpads 54-2 arranged in termination areas 54-3, that are preferablydisposed at or proximate to edges 54-4 of the substrate 53. The chippackage 54 may further include an encapsulant 54-5, such as an epoxy,that fixes the chip 52 in place within the package 54 as an integratedassembly along with associated cable connectors and other components.The chip package 54, as illustrated, be connected in part, to themotherboard by way of solder bumps 49, but such connections do notinclude high speed signal transmission lines in place on the motherboard62.

Cables 60 are terminated to the package contact pads 54-2 by suitablewire-to-board connectors and the like, and these cables 60 arepreferably of the twin-ax construction with two signal conductors 61surrounded by a dielectric covering 61-1 with an associated drain wire61-2 and an outer conductive covering 61-3 and a finished insulativeouter jacket 61-4. (FIG. 2D.) As noted above, the cables 60 and theirsignal conductor pairs define high speed signal transmission lines thatlead from the chip package 54 to the first (entry) or second (exit)connectors 80, 30. The ordered geometry of the cables maintains thesignal conductors as pairs in a preselected spacing to control theimpedance therethrough. Utilizing the cables as signal transmissionlines eliminates the need to lay down high speed signal transmissionlines in the form of traces on the motherboard, thereby avoiding highcosts of exotic board materials and the losses associated with cheaperboard materials such as FR4.

As illustrated in FIGS. 2-2C, the cables 60 have opposing first andsecond, or near and far ends 163, 164 that are respectively connected tothe chip package 54 and the I/O connector ports 80 or backplaneconnectors 30 to define high speed signal transmission lines that bypassthe motherboard. These connectors can be considered as “entry” and“exit” connectors of the host device in that they provide externalinterfaces for signals that first “enter” the device through, forexample, the I/O connector ports 80 at the front of the device 50 andfor signals that “exit” the device through the backplane connectors 30shown at the rear of the device. The cables 60 maintain the orderedgeometry of the signal conductors throughout the lengths they traverseto and from the chip via the external interfaces. The ordered geometryof the cables permits the cables to be turned, bent or crossed in theirpaths without introducing problematic signal reflection or impedancediscontinuities into the transmission lines which can occur in circuitboard signal transmission lines. The cables 60 are arranged in first andsecond sets of cables, with the first cable set extending between theentry connector ports and the chip package 54, and the second set ofcables extending between the chip package 54 and the exit connectors 30in the second wall 57 of the device. The manner in which the signalconductors of the cables 60 may be terminated to the chip substrate canvary. As illustrated in FIG. 2C, the cables 60 may be terminated by wayof wire-to-board connectors 25, which mate with contacts on the chippackage substrate 54, either on the surface thereof or in matingconnectors. Heat sinks 71 may be attached to surfaces of the chips 52 asshown to dissipate heat, or integrated into the assembly by way of theencapsulant.

The chips, substrate, heat sink and cable connectors 25 may integratedtogether by way of an encapsulant or other means that holds themtogether as a single assembly as shown in FIGS. 2-2C. This structurepermits a device designer to fully utilize the space available on themotherboard 62 for additional components and circuit which add value tothe host device without the need for complex circuit board designs.These integrated assemblies can be inserted into devices by merelyinserting the entry and exit connectors into respective openings in thefront and back walls 374, 57 of the host device 50. Ancillary connectorsmay be provided for connecting the chip package to other circuits of thedevice as shown in FIG. 3B. The assemblies may also be provided in otherforms, such as, for example: 1) without the chip package, but with thechip package substrate; 2) with the chip package and either the entry orexit connectors, shown respectively at 400 and 401 in FIG. 2A; and, 3)with both the entry and exit connectors arranged to extend to openingsin the front wall of the device, as shown at 402 in FIG. 2. In thismanner the assemblies 400, 401 and 402 may be inserted into a basicdevice to provide the device with its functionality without the need todesign such functionality into the motherboard 62 of the hose device 50.

Turning to FIGS. 4, 7 & 8, an internal connector 70 constructed inaccordance with the principles of the present disclosure is receivedwithin the connector ports 80 and includes an insulative body 108 thatincludes a card-receiving slot 109 that opens to the front of theconnector 70 and to the entrance 67 of the port 80. The card-receivingslot 109 is positioned above a polarizing channel 110 formed by legs 110a, 110 b that support the card-receiving slot 109 off of the bottom wall68 of the port 80 and prevent incorrectly positioned opposing matingconnectors from being inserted into the card slot 109. The connectorbody 108 has a plurality of terminal-receiving cavities 111 aligned onopposite sides of the card slot 109 which receive contact portions ofcantilevered terminals 115 a, 115 b of two connector elements 104 a, 104b. The connector elements 104 a, 104 b support the terminals 115 a, 115b in respective single rows of terminals as illustrated in FIGS. 4A and8C. The two connector elements 104 a, 104 b each have wafer-likeconfigurations and are inserted into the connector body 108 from therear to complete the internal connector assembly. The terminal arrays ofeach connector element 104 a, 104 b are thereby positioned on oppositesides of the card-receiving slot 109 as shown.

FIG. 8A illustrates the basic construction of a connector element 104that is used in the connectors 70 of the present disclosure. A pluralityof twin-ax cables 60 and regular wires 121 are arranged in an arrayextending widthwise of the connector 70. The ends of the wires 121 andcables 60 are stripped to expose the signal conductors 61 of the cables60 as well as define free ends 121 a, 120 a of the wires and cables,respectively, for terminating to corresponding tail portions 116 of theconnector terminals 115 a, 115 b. (FIG. 4A.) In the embodimentillustrated, pairs of the twin-ax cables 60 are located at the outerends of the array, and the drain wires 61-2 of the twin-ax cables 120are bent simply upwardly and then bent again to lie flat on theirassociated ground plates 125. The terminals 115 a, 115 b are heldtogether in their own spaced apart widthwise array by a support bar 124.This largely maintains the geometry of the cable in the connectortermination.

The receptacle connector 70 has a structure that promotes the signalintegrity of data signals passing therethrough and which provides animpedance transition from the bypass cable wire pairs and the circuitsof a circuit card of an opposing mating connector. This transition isfrom 85 to 100 ohms within a preselected tolerance level and is done instages, or three zones so that the transition occurs in a gradual mannerfrom an entry level impedance to a first transition impedance and then asecond transition impedance and then finally to the final or thirdtransition impedance. In this manner, the impedance transition occurs ina somewhat gradual manner over the entire length of the receptacleconnector rather than occurring in the tail or the contact portions ofthat connector.

This gradual transition is provided by presenting three differentdielectric mediums through which the receptacle connector terminalsextend. The first zone medium is preferably a hot melt adhesive in whichthe impedance rises by about 6 ohms from the incoming impedance of about85 ohms, and the second zone medium preferably includes LCP (liquidcrystal polymer) where the impedance rises by about another 6 ohms, andfinally the third zone medium includes air in which the impedance risesto about 105 ohms, thereby transition the impedance with a tolerancelevel of about 5%. The changes in surrounding medium are alsoaccompanied by changes in the width of the terminals becoming wider ornarrower in different zones. The distances between the terminals andassociated ground planes can also contribute to this selected tuning ofthe impedance. The transition occurs over the length of the connectorfrom the tails to the contact ends to present a gradual increase over aunit length rather than sole in either the tail or the contact portionsof the terminals.

The termination areas of the cables/wires 120, 121 to the terminals 115a, 115 b are disposed in a nest, or cradle 130, that extends widthwiseand which is formed from an insulative material having a desireddielectric constant. (FIGS. 8A-8D.) The termination nest 130 has aU-shaped configuration and it is located adjacent the terminal supportbar 124. In this area, the drain wires 61-2 of the cables 60 are joinedto buss bars in the form of ground plates 125 that are positioned abovethe cables 60 and are spaced vertically apart from and above theterminal tail portions 116. The ground plates 125 have a plate body 125a with at least a partially planar surface which the drain wires 61-2contact and to which the drain wires may be soldered, or otherwiseconnected.

Contact legs 126 are provided as part of the ground plates 125 in orderto form contact portions 128 of the ground plates 125 that arepreferably attached to the tail portions 116 of ground terminals of theconnector 70. The contact legs 126 are vertically offset so that theground plates 125 are spaced apart from and extend over at least aportion of the termination of the signal conductors to the signalterminal tail portions in the row of terminals associated with acorresponding connector element. As shown in FIGS. 8B-8D, each of theground plates 125 preferably include three legs 126 which contact theground terminals of the connector 70 in a manner such that any twosignal terminal tail portions are flanked by two of the contact legs126. This arrangement permits the spacing of the signal terminals toapproximately match that of the signal conductors of the twin-ax cables60 from an impedance perspective. In this manner, a G-S-S-G pattern ofthe terminals 115 a, 115 b is maintained for the internal connector 70within the two rows of terminals on opposite sides of the card-receivingslot 109.

A rectangular frame 132 is provided along the rear of each connectorelement 104 a, 104 b and includes four walls 133 (FIG. 8) joinedtogether around a bottom wall 134 to at least partially define a hollowinterior recess 138. The front and rear walls 133 of the frame 132 areperforated as shown with openings 135 that are configured to accommodatethe twin-ax cables 120 and the low power and logic control wires 121 intheir longitudinal extent through the frame 132. The frame 132 is joinedto the cradle 130, along its rear face, by an overmolded portion thatfills the termination area. The connector element frame 132 is formed ofa conductive material, such as metal, or may have an outer conductivecoating, so that when in place within the connector port 80, theconnector elements 104 a, 104 b make electrical grounding contacttherewith. The connector element frames 132 are positioned adjacent toand rearward of the termination nest (FIG. 8C) and may be fixed to it asnoted below.

The sidewalls 133 of the frame 132 may be slotted as shown with verticalslots 136. These slots 136 will engage the sidewalls 106 a. 106 b of therear opening, or exit 106, of the connector port 80 and, because theframes are conductive, they can also alleviate EMI leakage out of therear opening 106 of the connector port 80. The open recess 138 of theconnector element frame 132 through which the cables and wires extend isfilled with a dielectric material, such as a liquid crystal polymer(“LCP”) that fixes the cables/wires in place in the recess 138 withrespect to the connector element frames 132 and to the termination nest,which also receives some of the LCP. In this manner, the wafer-likeconfiguration of the connector elements 104 a, 104 b is defined and thisoverall structure provides a measure of strain relief to the twin-axcables 60.

The bottoms 134 of the two connector elements 104 a, 104 b abut eachother and may engage each other through a post 140 and hole 141 mannerof engagement as shown in FIG. 6. In this manner, the two connectorelements 104 a, 104 b may be inserted into a rear opening of theconnector body 108 so that the terminal contact portions are alignedwith each other and are received in the terminal-receiving cavities 111of the connector body 108 to form an integrated connector assembly. Asillustrated in FIG. 6, the connector assembly is pressed into the hollowinterior space of the connector port 60 from below. An internal groundplane 142 is provided in the form of a flat, conductive plate that islocated between the two connecting elements 104 a, 104 b. It extendsfrom the rear end of the connector element frame 132 to the forward edgeof the termination nest 130. This ground plane 142 acts as a primaryground plane that serves to block crosstalk between the signal conductorpairs in one connector element and the signal conductor pairs in anotherconnector element. The ground plates 125, act as secondary groundplates, or busses to the signal conductors of the cables 120 and theirtermination to the signal terminals 115 a.

The slots 136 on the sides of the connector elements 104 a, 104 b engagethe sides 106 a, 106 b of the connector port rear opening 106, while twocatches 144 disposed on opposite exterior sides of the connector body108 are received in corresponding openings 146 in the sidewalls 64 a, 64b of the port 80. The catches 144 may be oversized so as to deform whenthe connector assembly is inserted into place in the housing body 63.The slots 136 may be rounded in configuration with tips 148 pointinginwardly or at each other, in order to ensure reliable contact with theconnector port 80. (FIG. 10.)

The two EMI absorbing pads 102 a, 102 b may be applied to opposingsurfaces of the connector elements 104 a, 104 b of the connectorassembly prior to the connector assembly being pressed into the interior61 of the port 80 from the bottom. The connector elements are verticallyslotted, as previously noted, so they can engage the sides 106 a, 106 bof the rear wall opening 106 of the port and this contact provides incooperation with the EMI-absorbing pads, four-sided EMI leakageprotection around the connector elements. The rear wall of the port 80and the conductive connector elements 104 a, 104 b combine to form, ineffect, a fifth wall that prevents EMI leakage. The pads 102 a, 102 bseal off the spaces between the connector elements 104 a, 104 b andopposing surfaces of the housing body 63. These pads 102 a, 102 b occupythe open spaces above and below the connector elements 104 a, 104, whichare normally empty in conventional ports.

The EMI pads 102 a, 102 b are preferably aligned with and positionedabove the areas of the connector elements where the cable wires areterminated to the terminal tails of the internal connector 70. Thebottom pad 102 b is held between the bottom wall 68 and the bottomconnector element 104 b, while the top pad 102 a is held in placebetween the top connector element 104 a and the module housing rearcover 90. This is accomplished by ribs 103 that are formed on the bottomof the rear cover 90 which extend down into contact with the pad 102 a,as illustrated in FIG. 14B. The connector elements, EMI-absorbing padsare thereby sandwiched between the housing body top and bottom walls 66,68 and the pads 102 a, 102 b ensure that EMI leakage is reduced alongthe housing body rear wall opening 106.

With the twin-ax cables 60 directly terminated to the terminals of theconnector 70, the ports 80 are configured for mounting off of a circuitboard and onto a panel or in a manner so as to be a free-standingconnector within a host device. The ports 80 need not be mounted to acircuit board 62 in a termination manner, but can be by way of fastenersextending through openings in the circuit board and into the screwbosses. The sealing off of the bottom of the port and elimination of theneed for a right-angle connector not only eliminates the need to mountthe connector port on the motherboard 62, but also facilitates stackingof the ports in both vertical and horizontal arrangements.

Accordingly, the wires of the connector may be directly connected tocomponents of the host device, such as a processor or a chip package andthe like bypassing the traces on the circuit board. As the connectionnow may be direct, the connector does not have to be mounted on acircuit board, but may be enclosed within a structure such as theconnector ports 80 disclosed and panel mounted. The connector ports 80may take the form of an adapter frame, a shielding cage of similar typeof housing. Still further, the connector port may be used an as internalconnecting sleeve to provide an internal connector port that ispositioned within the host device and which receives a plug-styleconnector. The connector port cables are terminated to the connectorelement terminal tails at one ends of the cables so the cables can beterminated at their second ends to the chip packages or processors ofthe host device. An integrated bypass assembly such as this can beinstalled and removed or replaced as a unit, which bypasses the circuitboard and the associated loss problems which occur in FR4 materials,thereby simplifying the design and reducing the cost of the circuitboard.

Turning now to FIGS. 4-9, a connector port/housing is illustrated inFIGS. 5 and 5A at 80 which is used as an external interface thataccommodates entry connectors of the host device. The port 80 isdisposed in the first wall 374 of the device 50 and receives opposingmating connectors in the form of plug connectors, such as pluggableelectronic modules and the like. The connector port 80 includes aconductive housing body 63 that includes two sidewalls 64 a, 64 b, arear wall 65 and top and bottom walls 66 and 68. All of the wallscooperatively define a hollow interior 61 that receives a correspondingopposing external mating connector that mates with an internal connector70. The walls of the port 80 may be formed together as one piece as inan adapter frame, or they may be utilize separate elements that arejoined together to form an integrated assembly. The connector port 80may be referred interchangeably herein as a “module housing” or a“housing,” but it will be understood that the port 80 is not limited inits operation to accommodating only pluggable modules, but willaccommodate any suitable connector.

The housing walls 64-66 & 68 are all conductive and provide shieldingfor connections made within the port 80. In this regard, the port 80 isprovided with a conductive bottom wall 68 that completely seals off thebottom of the housing body 63 in contrast to known cages and frames thatare open at their bottoms to the circuit board upon which they aremounted. The housing 80 contains an internal, cable-direct connector 70(FIG. 4) that has direct wire connections made to its terminals 115 a,115 b and therefore does not require termination to traces on themotherboard 62 of the host device 50. Prior art connectors enclosed bycages or frames are of the right angle type, meaning the connectorextends at a right angle from its mating face to the circuit board andthe traces to which the connector is terminated. Right angle connectorterminations to circuit boards create signal integrity problems in highspeed operation, due to the varying lengths of the terminals and thebending thereof, such as increased capacitance in the corners of thebends and jumps or dips in the characteristic impedance of the system atthe connector and its interface with the circuit board. Similarly, theexiting of the cables out of the rear of the housing eliminates the needto use press-fit pins as a means to mount the connector port to thecircuit board, as ordinary mounting holes can be used for threadedfasteners, thereby simplifying the overall design of a host devicemotherboard. The internal connectors 70 are terminated to wires ofcables 60 and exit out of the rear wall 65 of the housing 80, therebyavoiding the aforementioned problems.

The bottom wall 68 of the housing, as shown in FIGS. 5-6B, seals off thebottom of the housing 80. The bottom wall 68 is shown as formed from apiece of sheet metal with a bottom plate 72, and side attachment flaps73 that extend along the outer surfaces of the housing sidewalls 64 a,64 b. Openings 74 in the attachment flaps 73 engage catches, or tabs 76which are located on the sidewalls 64 a, 64 b and retain the bottomplate 72 in place. Additional means of attachment may include innerflaps 75 that are also bent up from the bottom plate 68 but arepositioned along the edges of the bottom plate 68 to extend into theinterior hollow space 61 along the inner surfaces of the sidewalls 64 a,64 b. Two such inner flaps 75 are illustrated in FIGS. 11 & 13A andinclude contact tabs 75 a that extend inwardly for contacting oppositesides of an opposing connector inserted into the interior channel 61.Two rims, or flanges 77 a, 77 b, may also be provided at opposite endsof the bottom plate 68 which extend at an angle thereto in order toengage the front and back wall 65 of the housing 80 to make conductivecontact and provide EMI shielding at those locations. The use of abottom wall 68 that covers the entire bottom significantly reduces EMIin this area. Standoffs 69 may be formed in the bottom wall 68 ifdesired. The many points of contact between the bottom wall 68 and thehousing body 63 provide a reliable EMI shielding gasket along the entirebottom of the port 80 for the internal connector 70.

Turning now to FIG. 5, the top wall 66 preferably includes an accessopening 81 which communicates with the hollow interior 61 and which isaligned with the internal connector 70 and primarily the area in frontof the internal connector 70. A heat transfer member 82 shown as afinned heat sink may be provided which has a base 84 that extends atleast partially into the access opening 81. The base 84 has a flatbottom contact surface 85 that contacts an opposing surface of a moduleinserted into the housing interior 61. Two retainers 86 are shown asjoined to the top wall 66 and each retainer 86 has a pair of preloadedcontact arms 88 that exert a downward retention force on a top plate 87of the heat sink. An EMI gasket 89 is provided that extends around theperiphery of the opening 81 and is interposed between the top wall 66and the heat transfer member 82.

The housing 80 further includes a rear cover portion 90 that extendsover a rear portion of the interior 61 to cover part of the internalconnector 70. A recess 91 may be formed in the rear cover 90 toaccommodate a chevron-shaped EMI gasket 92 interposed between opposingsurfaces of the rear cover 90 and the top wall 66. The rear cover 90 canbe seen to include an opening in the form of a slot 94. The top wall 66(FIG. 13A) may include an engagement hook 95 as shown that is receivedwithin the slot 94 to engage the top wall 66 to the housing body 63 in amanner such that the top wall 66 can be slid forward so that its leadingedge abuts the front flange of the housing 80, which may include aprojecting tab 96 formed therewith which engages a corresponding slot 97of the top wall 66. (FIGS. 5A & 13A.) Screws 99, or other fasteners maybe used to secure the top wall 66 onto the housing body 63 by engagingthreaded holes formed in screw bosses 100 supported by the housing body63. In this manner, the housing body 63 is sealed in a manner tosignificant reduce EMI leakage.

Because the internal connectors 70 are connected directly to the cables60, the housings 80 of the present disclosure need not be mounted to themotherboard 62 by direct termination, but can attached by way offasteners 120 that extend through openings 122 in the circuit board andinto the screw bosses 100. Sealing off of the bottom of the housing 80and elimination of a right-angle connector not only eliminates the needto mount the housing 80 on the motherboard 62 but also facilitatesstacking of the housings/ports 80 in vertical and horizontalarrangements. FIGS. 15 & 16 illustrate just two different styles ofstacking. FIGS. 15 & 15A illustrate a pair of housings 80 with theirentrances 67 oriented horizontally in a vertical stack. The two housings80 are shown supported on a circuit board 62 by way of bottom screws 120that engage the screw bosses 100 in an upward manner through openings inthe circuit board. A set of middle screws 124 are provided to engage thescrew bosses 100 of the lower housing and these screws 124 have threadedmale ends and threaded female ends 126. The female ends 126 engage topscrews 99, 128 extending into the screw bosses 100 of the top housing.Thus, multiple housings 80 of the present disclosure may be stacked insuch a fashion without requiring complex high speed connecting tracesformed in the circuit board 62 and terminated to the internal connectors70. Conventional stacking requires a dual connector that is terminatedto the circuit board at right angles which will possess the signalintegrity problems described above.

FIGS. 16-16A illustrate another manner in which the housings 80 of thepresent disclosure may be arranged. This arrangement includes ahorizontal row of three housings that are aligned vertically along afront of the host device, but raised off of the circuit board 62. FIG.16A illustrates a mounting nest 130 that has a base 132 and twoextending sidewalls 133 that form a recess which accommodates a housing80. The mounting nest 130 has two attachment flanges 134 that can beattached to a faceplate 136 with fasteners as shown extending throughopenings 135 in the base 132. Fasteners may be used to attach thehousings to the nest, and they extend through the base openings 135 intothe screw bosses 100. The top wall 66 of the housing 80 may be attachedto the housing body 63 with male-female ended fasteners 126 as notedabove so that adjacent housings 80 may be assembled into an integratedarrangement with male fasteners extending through the bases 132 of thenests 130 into the female ends 126 of opposing fasteners or into thescrew bosses 100 of the housing body. The housings 80 may also be spacedclosely together in instances as shown in FIGS. 14-16A as the heattransfer member 82 has its heat dissipating fins extending rearwardly ofthe housing body as set forth to follow.

Accordingly, a free-standing connector port/housing is provided that canbe attached to an external wall of a host device, such as a faceplate orbezel or to a circuit board without requiring any termination tracespositioned underneath the module housing. Such a free-standing port doesnot have to be mounted on a circuit board, but may be panel mounted. Theconnector port may take the form of an adapter frame, a shielding cageor similar type of housing. Still further, the connector port may beused an as internal connecting sleeve to provide an internal connectorport that is positioned within the host device and which receives aplug-style connector. The connector port cables are terminated to theconnector element terminal tails at the proximal ends of the cables, andthe cables can be terminated at their distal ends to the chip packagesor processors of the host device. An integrated bypass assembly such asthis can be installed and removed or replaced as a unit, which bypassesthe circuit board and the associated loss problems which occur in FR4materials, thereby simplifying the design and reducing the cost of thecircuit board.

The mating connectors used to connect to the I/O connectors generateheat during operation, and this heat must be removed in order tomaintain efficient transmitting and reception of signals duringoperation. High temperatures can negatively affect the performance ofnot only the modules, but also the devices in which they are used, so itis important to remove this operational heat. Such removal is typicallyaccomplished by the use of heat sinks which include solid bases thatmake contact with selected surfaces of the modules, typically the topsurfaces. These heat sinks further have plurality of heat-dissipatingfins that project upwardly from the bases into the interior space of thedevice. The fins are spaced apart from each other so that air can flowover and around the fins in a manner that heat is dissipated from thefins into the surrounding interior atmosphere. The fins are mountedabove the heat sinks and modules and extend upwardly for a specificheight in order to achieve a desired degree of thermal exchange.However, the use of such heat sinks does not permit a designer to reducethe height of the devices in which modules are used, eliminating thepossibility of reducing the overall heights of such devices.

We have developed a thermal transfer structure that is suitable for usewith electronic and other modules that are inserted into housings andguide or adapter frames. Such a structure may also be utilized forthermal transfer intentions on processors and integrated circuits, aswell.

In this regard, as shown in FIGS. 17-19G, a heat sink assembly 240 isprovided that includes a heat transfer portion 241 which has a solidbase 242 that depends downwardly into the interior space 226 of themodule housing/connector port 222. The heat transfer portion base 242 iscomplimentary in shape to the opening 232 in the housing 222 so that thebase portion 242 may extend through the opening 232 and into theinterior space 226 so as to make thermal contact with the top or uppersurface of a module inserted into the front opening 230 of the interiorbay 229 of the housing 222. The base 242 may further include a skirt orlip portion 244 that extends around at least a substantial portion ofthe periphery of the base 242, and preferably around the entireperiphery of the base 242. This skirt 244 is received in a correspondingrecess 246 formed in the top surface 233 of the housing 222 and whichpreferably surrounds the opening 232. A conductive EMI ring gasket 247is provided that fits in the recess 246 and which encircles the opening232. The gasket 247 has a plurality of spring fingers 248 that providesa conductive seal between the heat transfer portion skirt 244 and thehousing top recess 246 so as to prevent EMI leakage through the opening232. The EMI gasket 247 sits within the recess 246 and surrounds theopening 232 with the spring fingers 248 extending radially outwardly, asshown and into contact with the bottom surface of the skirt 244. Theopening 232 in the top of the housing 222 is considered as a contactopening as it permits the heat transfer portion 241 to extend into theinterior space 226 of the housing 222 and into thermal transfer contactwith any module inserted therein by way of a thermal contact surface250. (FIG. 19C.)

The heat transfer portion 241 has a solid base portion 242 thatpreferably includes a planar thermal contact surface 250 (on its bottom)that is configured to enter the frame contact opening and contact thetop surface of a module inserted into the bay 229 in effective andreliable thermal contact. The base 242 may include an angled lead-inportion on its contact surface 250 to facilitate the insertion of amodule. The heat sink assembly 240 further includes a distinct heatdissipating portion 252 that dissipates heat generated by the module andtransferred to the heat transfer portion 241 by way of contact betweenthe thermal contact surface 250 and an opposing top surface(s) of themodule. As shown in FIG. 18, this heat dissipating portion 252 isdistinct from the heat transfer portion 241 and is spaced aparttherefrom in a longitudinal or horizontal direction.

The heat dissipating portion 252 includes a base 254 that extends out ina cantilevered fashion from the heat transfer portion 241 along asimilar longitudinal axis. A plurality of vertical heat-dissipating fins256 are disposed on the base 254 and extend vertically downwardly fromthe heat dissipating portion base 254. As illustrated, the fins 256 arespaced apart from each other in the longitudinal (horizontal) directionto define a plurality of cooling passages 258 therebetween that arespaced away lengthwise from the heat transfer portion 241 and whichfurther extend lengthwise with respect to the modules. In order toretain the heat transfer portion 241 in contact with a correspondingmodule, and also resist any moment that may occur due to the weightand/or length of the heat dissipating portion 252, retainers 260 areillustrated. These retainers 260 are attached to the frame top surface233 by means of fasteners, such as rivets 262, which may be formed aspart of the housing 222 in the nature of vertical posts 263 that arereceived within corresponding openings 264 disposed in the retainer baseportion 265. The free ends of these posts 263 may be “dead-headed” or“mushroomed” to form the connection between the retainers 260 and theskirt 244. The retainers 260 are seen to have pairs of cantileveredspring arms 267 associated with them and which extend longitudinallyfrom the base portions 265 as illustrated. The spring arms 267 areflexible and are formed as elastic spring arms 267 with a preformeddownward bias. The spring arms 267 terminate in free ends 268 and theyextend at a downward angle into contact with the heat transfer memberskirt 244. Four such contact points are provided for the heat sink 240assembly illustrated in the Figures, and the contact points will definea four-sided figure when connected by imaginary lines. However, thecontact points of the spring arms 267 may vary from the locations shownaccording to the extent to which space is available on the skirt portion244 of the heat sink member 240.

The elasticity of the spring arms 267 permits a designer to obtain adesired contact pressure by configuring the length of the spring arm267, the depth to which the spring arm 267 depends down into the recess246 and the height of the stub 269 that joins the spring arm 267 to theretainer 260. The fastener connection of the retainer 260 to the skirtplate 244 eliminates forming and utilizing attachments on the sides ofthe housing 222 which would take up space and affect spacing betweenhousing 222. The rivets 262 also have a low profile so that the frame226 is not unduly enlarged in any direction, including the verticaldirection. The spring arms 267 are relatively short in length andtherefore contact the heat transfer portion 241 at approximately fourcorners thereof to exert a reliable contact pressure on it in order tomaintain it in good thermal transfer contact with any modules.

Uniquely, the heat-dissipating fins 256 are removed from immediatecontact with the heat transfer portion 241 of the heat sink assembly240. Rather, they are positioned on the heat dissipating portion 252 andthey extend downwardly therefrom. The fins 256 are longitudinally spacedaway from the heat transfer portion 41 and its base 242. The fins 256are further arranged in a series of planes, shown as vertical planes F,that intersect both the horizontal plane, H1, in which the heat transferportion skirt extends and the horizontal plane H2 in which the thermalcontact surface(s) 250 extend. As shown in FIG. 19C, not only do thevertical planes F intersect the two planes H1 and H2, but the finsthemselves extend for heights that intersect those two planes.Furthermore, adjacent fins 256 are separated by intervening coolingpassages or air channels through which air may circulate. The fins 256and cooling passages 258 extend transversely to a longitudinal axis ofthe heat sink assembly 240. In this manner, the fins 256 may occupy thespace R rearwardly of the housing 222 and above the wires 272 which areterminated to the receptacle connector 271 supported in the housing 222.Locating the fins 256 in this manner permits the overall height of thedevice in which the housing structures are used to be reduced byapproximately the height of the fins that ordinarily would projectupwardly from the housing. It is desired to have the fins 256 not touchthe wires 272 in this orientation. In this regard, the height of thefins 256 is preferably less that the height of the housing 222 asillustrated in the Figures.

The heat transfer and heat dissipating portions 241, 252 are shown asbeing integrally formed as one piece to promote heat transfer from thetransfer portion 241 to the dissipating portion 252. However, it iscontemplated that the two portions 241, 252 could be formed separatelyand subsequently joined together where desirable. In order to furtherenhance the transfer of heat from the heat transfer portion 241, athermal transfer member 274 is provided that extends lengthwise alongand in contact with the heat transfer and heat dissipating portions 241,252. Such a transfer member 274 is shown in the Figures as a heat pipe275, having an oblong, or elliptical, cross-sectional configurationwhich include major and minor axes that define such a shape. (FIG. 19D.)The oblong configuration of the heat pipe 275 increases the amount ofcontact area between the heat pipe 275 and the two portions 241, 252 ofthe heat sink assembly 240. Other non-circular configurations such as arectangular inner cavity may be utilized or even cylindrical ones. Theheat pipe 275 is received within a common channel 278 that also extendslongitudinally along the heat sink assembly 240 and it follows thecontour of the two portion 241, 252. Accordingly, the heat pipe 275 hasan offset configuration with two distinct portions 279, 280 that extendat the different heights, or elevations, of the heat sink assembly 240.

The heat pipe 275 is a hollow member with an inner cavity 282 defined bysidewalls 283 that is sealed at its ends and which contains a two-phase(e.g., vaporizable) fluid within its inner cavity 282. Examples of atwo-phase fluid that can reside within embodiments of inner cavity 282include purified water, freon, etc. The heat pipe 275 and its walls 283can be composed of aluminum, copper or other thermally conductivematerials. The inner cavity 282 preferably includes an evaporator region279 located adjacent the heat transfer portion 241 and a condenserregion 280 located adjacent the heat-dissipating portion 252. Heat istransmitted from the heat transfer portion 241 through bottom and sidewalls 283 of the heat pipe 275 into the inner cavity 282 where is cancause the two-phase fluid present in the evaporator region 279 toevaporate. This vapor can then be condensed to liquid in the condenserregion 280. In the illustrated embodiment, the vapor gives up heat as itcondenses, and that heat is transmitted out of the inner cavity 282through the walls 283 of the heat pipe 275 into the base of the heatdissipating portion 252 and its associated fins 256. The inner cavity282 may include a wick 284 to facilitate travel of the condensed liquidalong the wick back to the evaporator region 280. (FIG. 19D.) The wick284 may take the form of grooved channels on the interior surface of theinner cavity 282, or an extent of wire mesh or the like.

As illustrated, the heat transfer and heat dissipating portions 241, 252of the heat sink assembly 240 extend longitudinally but extend atdifferent elevations, with the heat dissipating portion 252 being raisedwith respect to the heat transfer portion 241. This difference inelevation facilitates, to some extent, the movement of the liquid vaporfrom the heat transfer portion 241 up into the heat dissipating portion252, but its primary purpose is to accommodate the heat dissipatingportion 252 in its horizontal extent without having to modify the frame222 to accommodate it. If one desired to extend the heat dissipatingportion 252 at the same elevation as the heat transfer portion 241, therear wall 224 and a portion of the top surface 233, proximate theretowould need to be modified. A channel, or recess, may be formed in thosetwo walls 224, 233 to accommodate the area of the heat sink assembly 40between the heat transfer and dissipating portions 241, 252. Also,although mostly one heat pipe 275 has been discussed, it is understoodthat multiple heat pipes, such as a pair of heat pipes 290, asillustrated in phantom in FIG. 19E may be routed in the heat sinkassembly channel. In this instance, the pair of pipes may beencapsulated in a medium that facilitates heat transfer to make up forthe amount of direct contact lost between a pair of heat pipes and asingle, oblong configured heat pipe as illustrated. Thermally conductivegreases or other compounds may be applied to the heat pipes to enhancethe thermal transfer.

This heat sink assembly thermally engages the module housing anduniquely transfers heat therefrom to an area rearwardly of the modulehousing. With this structure and its downwardly depending heatdissipating fins, the devices in which such heat sink assemblies areused can have a reduced height, permitting additional devices in closetsand stacks. The location of heat dissipating fins is such that all ofthe spaces between the fins are used for cooling as none of them havelight pipes or any other members extending therethrough. The heat sinkheat-dissipating portion extend horizontally but spaced above themotherboard of the device so a designer can utilize this open space foradditional functional components without increasing the lateral size anddepth of the host device. Examples of the manner in which the connectorports with the heat sinks integrated therewith can be arranged andmounted for use in a host device are illustrated in FIGS. 15-16A.

FIGS. 20-20C illustrate a connector port 320 having a housing 322 and anindicator light assembly 342 of the present disclosure. The housing 322has a hollow interior space 326 that is formed from a plurality ofinterconnected walls, such as sidewalls 323 a, 323 b, rear wall 324, topwall 327 and bottom wall 328. The housing 322 has a front end 325 thatincludes an entrance 328 that communicates with the hollow interior 326.The bottom wall 328 is preferably formed of sheet metal and may haveengagement flaps 329 that are formed to contact engagement lugs 329 aformed on sidewalls 323 a, 323 b of the housing 322. The bottom wall 328seals the bottom of the housing.

The housing 322 independently houses an internal receptacle connector330 that has a connector housing 331 that includes a card-receiving slot330 a in which a plurality of conductive terminals 331 a are disposed.(FIG. 20B.) The slot 330 a receives a mating blade, or edge card of acorresponding plug connector. The connector port 320 is intended formounting in an electronic device, such as a switch, server, router orthe like in a manner such that the entrance 326 thereof is supportedalong a face panel, or bezel 374. The terminals 331 a of the internalconnector 330 are connected to various circuits and components of thehost device by way of conductors enclosed in wires 332 that extendthrough the rear wall 324 of the housing 322. The front end 325 of thehousing 322 may include an EMI gasket interposed between the housing andthe panel 374. Other EMI gaskets can be supported within the entrance326.

An elongated heat transfer member 336 is shown that extends lengthwiseof the housing 322. As noted above, it has a base 338 and a cantileveredrear end 339 that extends past the rear wall 324 of the housing 322 andwhich contains a plurality of heat-dissipating fins 340 that extenddownwardly and widthwise of the module housing 322. The base 338 has aflat bottom surface which is intended to make contact with an opposingsurface of an inserted module in order to affect the transfer of heatfrom the module to the base portion and into the atmosphere by way ofthe heat-dissipating fins 340.

The housings 322 and their corresponding internal connectors 330 aremated for use in high speed data transmission applications. Eachhousing, typically when attached to a panel, defines a connector portfor a pluggable module that serves one or more data transmission lines,or channels. In order to indicate the operational status of thesechannels, indicator lights are utilized that are visible from the frontpanel. The lights can indicate by color or illumination if a port (andits associated channels) is connected, active, down or the like. Theseindicator lights facilitate the installation of data transmissiondevices and permit an installer to confirm proper operation of the portsand channels.

Prior art indicator systems, such as U.S. Pat. No. 5,876,239 mentionedin the Background Section above, have utilized plastic pipes as lighttransmission conduits. This involves usually mounting a lighting elementsuch as a light-emitting diode (LED) on the circuit board of the deviceand contacting the LED with one end of the plastic pipe. The other endof the pipe extends to the face panel and into a hole in the panel. Theproblem with such a structure is that the light pipes must often take anon-linear path. Turns, bends and offsets reduce the amount of lighttransmitted and when pipes for different channels are located close toeach other the colored light in one pipe may affect the color of thelight in the adjacent pipe, thereby creating visual crosstalk andpossibly effecting the indication of the correct operational status ofthe device ports.

FIG. 21 illustrates an indicator light assembly 342 constructed inaccordance with the principles of the present disclosure. In thisassembly 342, the LEDs 344 are brought as close as they can to theindicator openings 343 associated with each connector port without theuse of any plastic transmission material. This is done by mounting anarray of LEDs 344 onto a substrate 346. The substrate 346 may be acircuit board shaped in the form of a horizontal bar that extendswidthwise over the housing 322 as shown in FIGS. 20 & 20C. The LEDs 344may include bases 345 that are mounted to the substrate. When a circuitboard is used as the substrate 346, the LEDs 344 may be terminated tocircuits with end points at a termination area of the substrate. InFIGS. 20A and 20C, this is illustrated as a connector 347, preferably ofthe wire-to-board style. In order to connect the LEDs 344 to theirassociated operational circuits, typically on the device circuit board,a plurality of conductive wires 348 are provided and the distal ends 351of the wires 348 are terminated to a second connector 353, which ismateable with a corresponding opposing connector mounted to the circuitboard of the device.

The LEDs 344 and their supporting substrate 346 define a light bar thatmay be mounted on the module housing top wall 327 proximate to theentrance 326 and the face panel so that the LEDs 344 are received withinthe indicator openings 343 of a face panel 374. (FIG. 23.) The wires 348are by their very nature flexible and hence, a designer has manypossibilities for reduced space mounting of the assemblies 320. The needfor plastic pipes extending from the circuit board either behind oralongside the module housing to the front end 325 is eliminated. Also,there are no transmission losses to incur through bends and turns of thewires 348 as they transmit only low power signal to the LEDs 344. Ineffect, the indicating lights 344 are generated at the face plate andthe likelihood of dimmed lights or muted (through light crosstalk)lights is virtually eliminated, leading to correct operational statusindications. Locating the indicator lights near the faceplate or bezelfrees up space on the circuit board 321 behind and alongside the housing322, and facilitates lower design costs of the device.

A support bracket 49 is illustrated for supporting the LEDs 344 andtheir substrate 346 and the bracket 349 has an overall L-shape with aflat base 350 and one or more flanges 352 that extend at an angle to thebase 350, shown upwardly in FIGS. 20A and 20D. The base 350 may haveholes 356 that engage posts 357 formed as part of the housing top wall327 which may be dead-headed to attach the bracket 349 to the housing322. The flanges 352 may include rivets for attaching the substrate 346to the bracket 349. Due to its proximity to the heat transfer member336, the bracket 349 may include retainers in the form of spring arms360 that are elastically formed with a preload for exerting a retentionpressure on the heat transfer member 336 to maintain it in place on themodule housing 322 and in contact with the inserted module.

The bracket base 350 may include upright tabs 362 (FIG. 20A) to whichare joined cantilevered contact arms 364 that extend downwardlytherefrom at an acute angle thereto. The contact arms 364 terminate infree ends 366 that are formed with a preformed downward bias topreferably at least partially extend into the access opening 334 thatcommunicates with the hollow interior of the housing 322 in which theinternal connector 330 is located. When the heat transfer member 336 isengaged with the housing 322, the base 338 of the heat transfer member336 projects partially through the access opening and into contact withan inserted module. In this instance, the top surface of the base 338 iscontacted by the contact arm free ends 366 which exert a downwardretention force thereon.

The use of the light bar and flexible connecting wires as shown anddescribed facilitates the design on electronic devices. For example, asshown in FIG. 22, two or more housings 322 may be oriented horizontallywhile stacked vertically on top of each other. Because there is no lightpipe support structure associated with the bottom housing, it is easierto stack the two housings 322 together. This can be done by way offasteners, such as screws 370, 371 that are received withincorresponding bosses 368 that are formed as part of the housing 322. Oneset of screws 370 may engage the other set 371. FIG. 23 illustratesanother manner of stacking the housings 322 together that is facilitatedby the use of the indicator light assemblies 342 of the presentdisclosure. In these Figures, the module housings 322 are orientedvertically and stacked together horizontally. In this regard, mountingnests 376 are provided which have a general U-shape with a base portion378 that is flanked by two sidewalls 380. Openings 381 in the mountingnests 376 which are aligned with the fastener bosses 368 permit screws382 to be used to hold the three module housings 322 shown in FIG. 23.The distal connectors 353 of the LEDs 44 may engage other connectorsthat are easily located on the circuit board.

FIGS. 24-24A illustrate the use of the indicator light assembly 342 witha housing having a thermal transfer member 384 that has longitudinalheat-dissipating fins 385 separated by intervening airflow spaces 386.In this embodiment, as with the previously discussed embodiments, theLEDs 344 and the substrate 346 may be attached to or formed with thesupport bracket 349 to form an integrated, one-piece assembly. Theflexible connecting wires 348 can be routed alongside of the fins 385and held in place by supports such as wire combs 388. In this manner allof the spaces 386 between the fins 385 are used for cooling as none ofthem accommodate light pipes or light pipe supports.

The disclosure provided herein describes features in terms of preferredand exemplary embodiments thereof. Numerous other embodiments,modifications and variations within the scope and spirit of the appendedclaims will occur to persons of ordinary skill in the art from a reviewof this disclosure.

We claim:
 1. A module housing, comprising: a housing body having aplurality of walls cooperatively defining an interior bay configured toreceive a module inserted therein, the housing body having a frontentrance configured to permit insertion of a module therein; a heattransfer member engaging the housing body and having a base that atleast partially projects into the interior bay, the heat transfer memberincluding a thermal contact surface configured, in operation, to engagethe module inserted into the interior bay; a heat dissipating memberjoined to the heat transfer member and extending away from the heattransfer member lengthwise of the housing body in cantilevered fashionrearwardly of the housing body, the heat dissipating member including aplurality of heat-dissipating fins extending downwardly from the heatdissipating member in an area rearward of the housing body; an internalreceptacle connector supporting a plurality of signal and groundterminals; and, a plurality of cables terminated to the signal andground terminals, the cables extending out of a rear wall of the modulehousing.
 2. The module housing of claim 1, further including a heat pipethat extends lengthwise along the heat transfer and heat dissipatingmembers and is in thermal contact therewith.
 3. The module housing ofclaim 2, wherein the heat pipe has a non-circular configuration.
 4. Themodule housing of claim 2, wherein the heat transfer and heatdissipating members are vertically offset from each other and the heatpipe includes distinct evaporator and condenser regions, the condenserregion being disposed above the evaporator region.
 5. The module housingof claim 1, wherein the heat-dissipating fins extend to a level beneatha plane in which the thermal contact surface extends.
 6. The modulehousing of claim 1, wherein the cables have distal ends that areterminated to connectors.
 7. The module housing of claim 1, wherein thecables are configured to be terminated at distal ends thereof, to a chippackage.
 8. The module housing of claim 1, wherein the thermal contactsurface is biased so as to press, in operation, against the insertedmodule.
 9. A module housing, comprising: a housing body having aplurality of walls cooperatively defining an interior bay thereof forreceiving at least one module therein, the housing body having a frontentrance configured to permit insertion of a module therein; a heattransfer member engaging the housing body, the heat transfer memberincluding a thermal contact surface extending into the interior bay; aheat dissipating member joined to the heat transfer member and extendingaway from the heat transfer member lengthwise of the housing body incantilevered fashion rearwardly of the housing body, the heatdissipating member including a plurality of heat-dissipating fins awayfrom the heat dissipating member in an area rearward of the housingbody; an internal receptacle connector supporting a plurality of signaland ground terminals; and, a plurality of cables terminated to thesignal and ground terminals, the cables extending out of a rear wall ofthe module housing.
 10. The module housing of claim 7, further includinga heat pipe that extends lengthwise along the heat transfer and heatdissipating members and is in thermal contact therewith.